If you haven't heard of spiked seltzer, you might not be running with the right crowd. The bubbly libation packs a punch at around 6% alcohol by volume. It's low-carb, low-calorie and low-sugar, but it's certainly not low on fans this summer.

Hard seltzers have taken the 21-plus crowd by storm recently. The industry was worth about $60 million heading into last summer, but experts say the space has exploded more than 400% in the last year.

So what does that mean for light beer, which typically has around the same nutrition value and buzz-inducing qualities? If the behavior of some of the bigger brewers means anything, hard seltzer is a threat not to be taken lightly.